Man-made diamonds could unlock bionic eye

Bridie Smith

IT TAKES up to 3.3 billion years for nature to make a diamond. But physics professor Steven Prawer can cook them up in five days using the microwave-like reactor at his Parkville laboratory.

''They are made with methane and hydrogen,'' Professor Prawer said. ''You cook them in the microwave oven on high for five days and then you have lovely little diamonds.''

The diamonds - which come out black because of their tiny size which scatters the light - are likely to prove a key ingredient in Australia's $42 million quest to develop a bionic eye.

Diamonds have long been used in the body due to their durability and low rejection rate, with diamond coating applied to everything from heart valves to hip joints. They are also a common insulator. But Professor Prawer, inaugural head of the Melbourne Materials Institute at Melbourne University, said diamonds have never been used to stimulate the nerves.

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''We have discovered a form of diamond that we can make which is bio-compatible and very good as a stimulating electrode, which means we can put an electrical signal onto it that then causes the neurons to fire and get a response,'' he said.

It's this novel approach being taken by the multi-disciplinary team behind Bionic Vision Australia that has researchers most excited. ''I don't think anyone ever believed that diamonds could be used to stimulate [the ganglion cells] … this is a uniquely Australian approach,'' Professor Prawer said.

He said establishing that diamonds could be used to stimulate nerves could have future applications in the treatment of other conditions such as Parkinson's disease and epilepsy.

The man-made diamonds will also be used to encapsulate the five-square-millimetre microchip, the engine of the bionic eye, which will be implanted into the retina.

With pre-clinical trials under way, the Bionic Vision Australia consortium - including Melbourne University, the Centre for Eye Research Australia, NICTA, the Bionics Institute and the University of New South Wales - hope that the first human implant will take place next year at the Victorian Eye and Ear Hospital.

In 2009, the federal government committed $50 million over four years to develop the bionic eye in Australia. While Bionic Vision Australia secured the lion's share, Monash University received $8 million to work on an implant which will stimulate the visual cortex within the brain, bypassing the eye and optic nerve.